The present invention relates to the field of telecommunications networks in which terminals communicate via the UPnP protocol as defined by the UPnP (universal plug & play) Forum. By way of example, the network may be a home network or a local network.
In known manner, the UPnP audio/video (A/V) service carried by this protocol seeks to provide interoperability and interconnection between pieces of multimedia equipment without requiring them to be configured by the user. In particular, the user can easily make use of this protocol to share contents between the various pieces of multimedia equipment in the user's home network (e.g. sharing photographs between a game console and a mobile terminal). It should be observed that the term “sharing contents” is used herein to mean giving access to those contents, so as to be able to consult them, view them, execute them, download them, etc.
In the description below, reference is made to the UPnP A/V service to designate a set of pieces of multimedia equipment that are mutually interconnected by a local or home network and that use the UPnP protocol for communicating with one another over the network.
A device (e.g. a control device, a content server, a terminal, etc.) is said to be a UPnP A/V device if it complies with the UPnP A/V standard or with any other equivalent or derived standard, in particular if it uses a command protocol in accordance with such a standard.
In general, in architectures of the UPnP A/V service, a distinction is made between different types of UPnP A/V device: control devices known as digital media controllers (DMCs); content servers known as digital media servers (DMSs); and content playback devices known as digital media renderers (DMRs), digital media adapters (DMAs), and digital media players (DMPs).
In a UPnP A/V service, the control device DMC performs a role that is central since it serves to discover the other UPnP A/V devices of the network, and the services offered by those devices, and it serves to put a DMS server into communication with a playback device DMR, DMA, or DMP so that the device plays back a multimedia content indexed by the DMS server.
Historically, the UPnP A/V service has been used for exchanging local multimedia contents between different pieces of equipment of a home network in which they were hosted. However nowadays a desire is becoming apparent to share multimedia contents between the equipments of remote home networks.
In response to this expectation, in the context of its “remote access” working group, the UPnP Forum has proposed a new service based on virtual private network (VPN) technology. In known manner, that technology guarantees a high level of security for exchanges of contents between the remote networks.
Nevertheless, the solution proposed by the UPnP Forum needs to manage problems of Internet protocol (IP) address conflicts between the various home networks for which it is managing the interface. Since the addressing plans of home networks are private, it is common practice for them to be identical, at least in part. Similarly, managing and exchanging authentication keys for establishing VPN tunnels is a problem for which there is not at present any satisfactory solution.
There therefore exists a need for a solution that enables contents to be shared in secure manner between remote networks without suffering from those drawbacks.